Want to get more speed out of your asymmetric spinnaker and become more comfortable racing with this type of sail? It’s worth remembering, first off, that all your knowledge of speed with traditional symmetric spinnakers isn’t wasted when you get on a boat with an asymmetric. Several premises have proven to be fast under either kind of chute.
1. Move the Rig Forward
At the top of your list is pulling the rig forward when sailing downwind. This alone can have a huge effect on boatspeed because it projects the spinnaker away from the mainsail into clearer wind. Ease off your backstay for starters. You might want to sight up your rig after easing it to ensure that you don’t ease it so much that you create reverse fore-and-aft bend (we call this “inverting” the rig). In most boats, you’ll find you can ease the backstay a lot before this happens.
To get the rig farther forward still, use your jib halyard to pull the rig forward. After the jib or genoa comes down, the bowman hooks the halyard to the tack fitting and grinds the rig forward. You’ll be amazed how much farther forward the rig will go. On boats that use roller-furling systems on their headsail, you can’t use the jib halyard for this, but after you furl your headsail, you can tension your jib sheets, which will pull the slack out of your headstay and cant the rig forward. On my J/105, I ease the backstay to the point where it’s very slack, then tension both jib sheets. This moves the top of the rig forward and snugs up the backstay.
2. Nail the Trim
The second important technique to maximize downwind speed (which also applies to all types of spinnakers) is to trim your sails to further increase separation between spinnaker and mainsail. The trimmer’s goal should be to ease the sheet as much as possible, allowing the spinnaker to lift and float away from the main. On boats with asymmetrics, heeling the boat to windward also helps the spinnaker separate from the main because it projects the luff to windward of the boat. This is why you see the top boats in an asymmetric fleet sailing downwind with the whole crew packed to weather.
3. The Tack Line
The third key is to pay attention to the trim of the spinnaker’s tack line. I often wonder why racers with symmetric chutes constantly adjust the topping lift, but then, with an asymmetric, forget to do the same with the tack line, since adjusting it has a similar effect. If the luff of an asymmetric becomes too bouncy or hard to control, tighten the tack line. This straightens the luff and moves the draft forward in the sail, and settles it down—which is why I like to have the tack line a little tight for a set or jibe because it fills more quickly.
After we build speed and the pressure increases in the sail, we usually try easing the tack line to allow the chute to float away from the main and rotate to windward. I like to call this effect on an asymmetric “opening the luff.” When the luff opens and the sail lifts away from the boat, the upper sections of the luff are more pressured, and the luff flattens in curvature slightly. This is OK, because the spinnaker has pressure in it and remains stable while rotating to windward more and separating from the mainsail.
Here’s a general rule for tack-line tension: if the tack line is angled to leeward or if the luff of the sail becomes unstable, tighten the tack line; if the tack line is angled to windward and you want to try to open up the upper luff, ease the tack line.
4. Mainsail Trim
The fourth important factor in downwind speed with an asymmetric is how you trim the mainsail. The primary rule is to avoid overtrimming the main. I check the trim simply by easing the main until the luff starts to break and then bring it in until it stops breaking.
Vang trim is also important: On our J/105, at the first regatta in my new boat, we were slow downwind. I couldn’t figure what the problem was until we experimented with the vang tension, picking up speed by easing it more than we normally would aboard a boat with a conventional spinnaker.
Weight placement is also important, and as I said before, the key move on our boat is to position the crew to windward to project the spinnaker. At the same time, we focus on our fore-and-aft weight placement. Several of the J Boats designs have very full bows and like the weight forward downwind. I’ve also found this to be fast in a lot of other boats. In Stars and Etchells, for example, you often see a crewmember in front of the shrouds. The goal in weight placement is to reduce wetted surface, but not to plow the bow too much or lose control. In a Laser, keeping your weight forward is fast, but you risk losing control and getting wet.
The fifth factor that makes all the difference in speed downwind with an asymmetric is organizing your crew as a team. When sailing the J/80, each crewmember covers a key position, but on a larger boat, you can divide your crew to cover the same four areas.
The first position is that of the spotter/tactician, whose job is to help with the following critical decisions: First, the spotter keeps us all informed about the position and speed of our competition. Second, he provides me, the skipper, with information about our boat’s speed and angle relative to a specific boat or group of boats. He’ll say whether we’re lower or higher in angle and whether we’re faster or slower. The spotter also helps with tactical decisions, such as how to keep our lane clear and free from any wind shadows, and how to take advantage of windshifts or different sailing angles coming into the leeward mark.
The second position is that of the spinnaker trimmer, whose main job is to help the skipper sail the boat at the optimum sailing angle for the best VMG to the leeward mark. The trimmer’s goal should be to keep the sheet as eased as possible without the luff of the sail breaking. An equally important job is to constantly inform the skipper of the pressure on the sheet and in the sail. I find the trimmer’s advice most helpful when he repeatedly suggests how much or how little pressure is in the sail. He might say, for example, “I’m losing pressure on the sail, let’s try a little higher,” or “I have a lot of pressure, let’s fall off a little.” On bigger boats, the trimmer position becomes a team effort, with the grinder and trimmer working together to keep the sail in optimum trim while communicating with the helmsman.
On asymmetric boats, being ready to jibe at any time is the key factor in attacking the racecourse. The third crew position is that of the No. 2 trimmer, whose job is to be sure that we’re ready as soon as the previous maneuver is completed. This includes the following: 1. the current spinnaker sheet must be free to run out smoothly and completely; 2. the second trimmer, on the new sheet, must be in a place from which the new sheet can be trimmed efficiently and quickly; 3. the new spinnaker sheet is clear of the bow pulpit and high up on the headstay (around 6 to 8 feet up is best), ready for a fast trim.
During the jibe, the spinnaker trimmer working the old sheet stays with that sheet. His job is to make sure the clew floats to the headstay and then to be sure that the pressure is off his sheet so the new sheet can be trimmed rapidly on the new jibe. The second trimmer pulls in as fast as possible on the new sheet in an effort to refill the spinnaker quickly. Right after the spinnaker fills, he’ll normally ease it again to set the trim properly on the chosen angle for the new jibe.
The fourth job is the skipper’s—to sail the boat to the fastest VMG to the leeward mark. It’s his job to assimilate the information given to him by the trimmer and the spotter. Some skippers delegate the tactical decisions to the tactician; others make those decisions for themselves. What counts is that boatspeed and VMG are maximized while at the same time, the skipper defends the boat’s position on the racecourse.
In summary, we work together as a team to get the boat down the run, just as you would with a symmetric kite. The skipper looks for constant feedback from the others. The trimmer focuses on angle assessment and pressure on the sail. The second trimmer makes sure we’re always ready for the next move. And the tactician and spotter help keep the boat in the best position relative to our competition and the next mark.
Here are a few other simple but important downwind tips: Before a race, get out early to develop a good idea of the conditions and wind angles upwind and downwind. When going into a windward mark, ask yourself if you’re on a lift or a header. That will help you decide which tack you want to take down the run—typically, the headed jibe. And use a hand-bearing compass to help sight the leeward mark and then determine when to jibe.
Work hard to keep your air clear and avoid sailing under the fleet; in asymmetric boats it’s easy for boats behind to trap you and blanket you. And when you jibe, try to make every one of them count. Each jibe results in a loss in distance, so while you should take advantage of the shifts, don’t jibe just for the sake of jibing. In a J/105 on a 1.5-mile leg, two extra jibes will cost you at least four boat lengths.
My final thought on asymmetric boatspeed and teamwork is that you shouldn’t be afraid to practice and try different things. Use your speedo or GPS to help figure out the fastest way to sail. Also, record your downwind sailing angles. Besides building on your teamwork, this kind of practice will teach you to find these angles instinctively, which is invaluable when you’re trying to adjust to, or keep track of, the windshifts downwind during a race.